Broke 0.3 Vistas Fixed well documented Nov 8, 2018 their #74 worst broke on record

Windows 10 Pro downgraded itself to Home, opinions not requested

November 2018 activation issue deactivated licensed Windows 10 Pro installs

↳ caused by Windows 10 Pro activation outage (November 2018)

The market's verdict: -6.2% on MSFT in the week after.

Status: Fixed. Working as intended, eventually.

What actually happened

In the second week of November 2018, properly licensed Windows 10 Pro machines started reporting that Windows could not be activated, and some found themselves relabeled as non-genuine or nudged toward the Home edition they had not bought. The culprit was Microsoft's own activation infrastructure, not any change on the machines. Microsoft pointed affected users at the Activation Troubleshooter while it sorted out its servers, and the problem cleared up within days. For a company whose licensing system had already spent 2007 calling paying customers pirates, it was a welcome reunion.

This one is well documented.

Were you affected? Unbreak it

Activation restored server-side within days

Microsoft has acknowledged this issue; a fix ships in an out-of-band or next cumulative update. Check Windows Release Health before manual workarounds.

Timeline